Malignant tumors are the primary cause of death among the Japanese and are a significant cause of death among other people of the world. To control this dreaded disease, remarkable progress has been made using various types of therapy encompassing chemotherapy, surgical therapy, and radiotherapy. Recently chemotherapy has begun to gain ground in the control of specific types of cancer, including leukemia among relatively young patients. For solid tumors, however, surgical treatment is considered first and is the treatment of choice in most instances. Only a very few patients having solid tumors recover with chemotherapy alone.
The potency of most chemotherapeutic agents is insufficient to suppress cellular proliferation of solid tumors. Furthermore, various adverse effects associated with these chemotherapeutic agents pose a significant limitation to the application of chemotherapy.
A class of chemotherapeutic agents of special interest is antibiotics. A number of U.S. patents are known which disclose antibiotics having antitumor effects. In this respect, the following U.S. patents are disclosed along with the respective antibiotic:
______________________________________ Ohba 4,994,578 duocarmycin Saito et al. 4,946,957 DC-52 derivatives Horton et al. 4,870,058 14-acyloxy-2'-halo- anthracycline Stefanska et al. 4,824,944 enamine derivatives of daunorubicin and adriamycin Schmitz 4,302,470 acanthifolic acid Pinnert et al. 3,997,663 daurorubicin and derivatives ______________________________________
None of the above U.S. patents disclose the use of a xanthocillin to inhibit tumor growth.